Reduction of human blood O₂ affinity using dihydroxyacetone, phosphate, and pyruvate

Human blood oxygen affinity (BOA) was measured after blood from 6 normal donors was incubated with 4 concentrations of dihydroxyacetone (0.022, 0.044, 0.088, and 0.175 M) plus equimolar disodium phosphate and pyruvate (sodium salt) (0.013, 0.025, 0.05 and 0.1 M) in solutions labeled DDP x 1, DDP x 2, DDP x 4, and DDP x 8, respectively. Blood P₅₀ rose (BOA was reduced) from a control value of 26.0 ± 0.4 Torr (mean ± SD) to 29.4 ± 0.6, 30.6 ± 0.4, 31.9 ± 0.15, and 33.3 ± 1.4 Torr after 2 hr of incubation at 37° C with solutions DDP x 1, DDP x 2, DDP x 4, and DDP x 8, respectively. P₅₀ changes at 2 hr were 75% complete within 30 min. During these incubations, erythrocyte 2,3-diphosphoglycerate (2,3-DPG) concentration rose from 0.76 ± 0.09 mol/mol Hb (control) to 1.09 ± 0.17, 1.14 ± 0.10, 1.33 ± 0.15, and 1.45 ± 0.25 mol/mol Hb with increasing solution concentration. BOA is decreased by an increase in erythrocyte 2,3-DPG. Reduced BOA may improve oxygen delivery to ischemic tissues.